Android greenDao

1.添加配置：

 

// In your root build.gradle file:
buildscript {
    repositories {
        jcenter()
        mavenCentral() // add repository
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.1'
        classpath 'org.greenrobot:greendao-gradle-plugin:3.2.2' // add plugin
    }
}

 

// In your app projects build.gradle file:
apply plugin: 'com.android.application'
apply plugin: 'org.greenrobot.greendao' // apply plugin
 
dependencies {
    implementation 'org.greenrobot:greendao:3.2.2' // add library
}

2.在App的build.gradle中添加配置：

 

  apply plugin: 'org.greenrobot.greendao' // apply plugin
  greendao {
        schemaVersion 2
        daoPackage 'test.zc.com.testgreendao.db.dao'    // 自动生成dao文件目录
        targetGenDir 'src/main/java'     
    }

3.在项目中创建实体类

 

@Entity
public class Bean {
    @Id(autoincrement = true)
    private long id;
    
    private String test;
}

4 Ctrl + 9 或者Build->Make Project,重新构建项目

构建成功后，GreenDao会在test.zc.com.testgreendao.db.dao生成如下文件：

 

// THIS CODE IS GENERATED BY greenDAO, DO NOT EDIT.
/**
 * Master of DAO (schema version 2): knows all DAOs.
 */
public class DaoMaster extends AbstractDaoMaster {
    public static final int SCHEMA_VERSION = 2;

    /** Creates underlying database table using DAOs. */
    public static void createAllTables(Database db, boolean ifNotExists) {
        BeanDao.createTable(db, ifNotExists);
    }

    /** Drops underlying database table using DAOs. */
    public static void dropAllTables(Database db, boolean ifExists) {
        BeanDao.dropTable(db, ifExists);
    }

    /**
     * WARNING: Drops all table on Upgrade! Use only during development.
     * Convenience method using a {@link DevOpenHelper}.
     */
    public static DaoSession newDevSession(Context context, String name) {
        Database db = new DevOpenHelper(context, name).getWritableDb();
        DaoMaster daoMaster = new DaoMaster(db);
        return daoMaster.newSession();
    }

    public DaoMaster(SQLiteDatabase db) {
        this(new StandardDatabase(db));
    }

    public DaoMaster(Database db) {
        super(db, SCHEMA_VERSION);
        registerDaoClass(BeanDao.class);
    }

    public DaoSession newSession() {
        return new DaoSession(db, IdentityScopeType.Session, daoConfigMap);
    }

    public DaoSession newSession(IdentityScopeType type) {
        return new DaoSession(db, type, daoConfigMap);
    }

    /**
     * Calls {@link #createAllTables(Database, boolean)} in {@link #onCreate(Database)} -
     */
    public static abstract class OpenHelper extends DatabaseOpenHelper {
        public OpenHelper(Context context, String name) {
            super(context, name, SCHEMA_VERSION);
        }

        public OpenHelper(Context context, String name, CursorFactory factory) {
            super(context, name, factory, SCHEMA_VERSION);
        }

        @Override
        public void onCreate(Database db) {
            Log.i("greenDAO", "Creating tables for schema version " + SCHEMA_VERSION);
            createAllTables(db, false);
        }
    }

    /** WARNING: Drops all table on Upgrade! Use only during development. */
    public static class DevOpenHelper extends OpenHelper {
        public DevOpenHelper(Context context, String name) {
            super(context, name);
        }

        public DevOpenHelper(Context context, String name, CursorFactory factory) {
            super(context, name, factory);
        }

        @Override
        public void onUpgrade(Database db, int oldVersion, int newVersion) {
            Log.i("greenDAO", "Upgrading schema from version " + oldVersion + " to " + newVersion + " by dropping all tables");
            dropAllTables(db, true);
            onCreate(db);
        }
    }

}

 

// THIS CODE IS GENERATED BY greenDAO, DO NOT EDIT.

/**
 * {@inheritDoc}
 * 
 * @see org.greenrobot.greendao.AbstractDaoSession
 */
public class DaoSession extends AbstractDaoSession {

    private final DaoConfig beanDaoConfig;

    private final BeanDao beanDao;

    public DaoSession(Database db, IdentityScopeType type, Map>, DaoConfig>
            daoConfigMap) {
        super(db);

        beanDaoConfig = daoConfigMap.get(BeanDao.class).clone();
        beanDaoConfig.initIdentityScope(type);

        beanDao = new BeanDao(beanDaoConfig, this);

        registerDao(Bean.class, beanDao);
    }
    
    public void clear() {
        beanDaoConfig.clearIdentityScope();
    }

    public BeanDao getBeanDao() {
        return beanDao;
    }

}

以及dao文件

 

// THIS CODE IS GENERATED BY greenDAO, DO NOT EDIT.
/** 
 * DAO for table "BEAN".
*/
public class BeanDao extends AbstractDao {

    public static final String TABLENAME = "BEAN";

    /**
     * Properties of entity Bean.

     * Can be used for QueryBuilder and for referencing column names.
     */
    public static class Properties {
        public final static Property Id = new Property(0, long.class, "id", true, "_id");
        public final static Property Test = new Property(1, String.class, "test", false, "TEST");
    }


    public BeanDao(DaoConfig config) {
        super(config);
    }
    
    public BeanDao(DaoConfig config, DaoSession daoSession) {
        super(config, daoSession);
    }

    /** Creates the underlying database table. */
    public static void createTable(Database db, boolean ifNotExists) {
        String constraint = ifNotExists? "IF NOT EXISTS ": "";
        db.execSQL("CREATE TABLE " + constraint + "\"BEAN\" (" + //
                "\"_id\" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL ," + // 0: id
                "\"TEST\" TEXT);"); // 1: test
    }

    /** Drops the underlying database table. */
    public static void dropTable(Database db, boolean ifExists) {
        String sql = "DROP TABLE " + (ifExists ? "IF EXISTS " : "") + "\"BEAN\"";
        db.execSQL(sql);
    }

    @Override
    protected final void bindValues(DatabaseStatement stmt, Bean entity) {
        stmt.clearBindings();
        stmt.bindLong(1, entity.getId());
 
        String test = entity.getTest();
        if (test != null) {
            stmt.bindString(2, test);
        }
    }

    @Override
    protected final void bindValues(SQLiteStatement stmt, Bean entity) {
        stmt.clearBindings();
        stmt.bindLong(1, entity.getId());
 
        String test = entity.getTest();
        if (test != null) {
            stmt.bindString(2, test);
        }
    }

    @Override
    public Long readKey(Cursor cursor, int offset) {
        return cursor.getLong(offset + 0);
    }    

    @Override
    public Bean readEntity(Cursor cursor, int offset) {
        Bean entity = new Bean( //
            cursor.getLong(offset + 0), // id
            cursor.isNull(offset + 1) ? null : cursor.getString(offset + 1) // test
        );
        return entity;
    }
     
    @Override
    public void readEntity(Cursor cursor, Bean entity, int offset) {
        entity.setId(cursor.getLong(offset + 0));
        entity.setTest(cursor.isNull(offset + 1) ? null : cursor.getString(offset + 1));
     }
    
    @Override
    protected final Long updateKeyAfterInsert(Bean entity, long rowId) {
        entity.setId(rowId);
        return rowId;
    }
    
    @Override
    public Long getKey(Bean entity) {
        if(entity != null) {
            return entity.getId();
        } else {
            return null;
        }
    }

    @Override
    public boolean hasKey(Bean entity) {
        throw new UnsupportedOperationException("Unsupported for entities with a non-null key");
    }

    @Override
    protected final boolean isEntityUpdateable() {
        return true;
    }
    
}

5.使用GreenDao：

为了方便使用我们稍做封装：

 

public class DbHelper {
    private static final String DATABASE_NAME = "zc.db";

    private DbHelper(){}

    private static class Helper{
        private static DbHelper dbHelper = new DbHelper();
    }

    public static DbHelper getHelper(){
        return Helper.dbHelper;
    }

    private DaoSession mDaoSession;

    public void  init(Context context){
        DaoMaster.DevOpenHelper devOpenHelper = new   
              DaoMaster.DevOpenHelper(context, DATABASE_NAME, null);
        DaoMaster daoMaster = new 
        DaoMaster(devOpenHelper.getWritableDatabase());

        mDaoSession = daoMaster.newSession();
    }

    public DaoSession getDaoSession(){
        return mDaoSession;
    }
}

在Application中初始化：

 

public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        DbHelper.getHelper().init(this);
    }
}

作者：SubDragon
链接：https://www.jianshu.com/p/933a71ec0adf
来源：简书
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